1. Field of the Invention
This invention relates to an electronic assembly, apparatus and process for scanning input information from patient information cards, processing the information and imaging the processed information on films and, in particular, on X-ray films in automatic daylight film handling systems.
2. Description of Related Art
Until the advent of automatic film handling systems, film sheets, and in particular X-ray film sheets, were handled manually by loading the film sheet into a cassette in the dark, exposing it under daylight conditions and then taking the cassette into a darkroom, opening it and placing the film sheet into a processor all in the dark.
Prior to the use of automatic film handling systems, printed labels were applied by adhesives to radiographs after the film was processed, i.e., developed. Later, but still before the use of automatic film handling systems, a separate and distinct direct image camera was used to imprint patient identification on radiographs prior to inserting the cassette or film into a film processing machine. See, for instance, U.S. Pat. No. 3,221,620.
Various systems are now available for the automatic handling of photographic film sheets and, in particular, X-ray film sheets (or radiographs) in daylight conditions. Most automatic film handling systems do not enable films to be labelled by the system. Instead, prior to insertion into the automatic film handling system, patient data and other information including time and date which are useful for tracking and legal purposes must be added to the film in a stand alone workstation or a workstation attached to feed the film exposed with patient ID information or the cassette containing the film exposed with patient ID information into an entrance port of the automatic film handling system. See, for instance, U.S. Pat. Nos. 3,836,783 and 3,888,587.
One prior art automatic film handling system includes a direct imaging camera within the system itself. Patient information is printed on a card. The card is flash illuminated. The reflected image is directed by lenses, prisms and mirrors directly onto a previously unexposed area of the film prior to processing. Other information, such as time and date, can be added by reflecting a light beam onto a representation of the time and date. The light reflected from the representation of the time and date is combined with the light reflected from the card such that both the card information and the other information is reflected onto the previously unexposed area of the film prior to development of the film.
It is desirable to image patient information on a film such that the image is readable (i.e., right reading) by a radiologist when the radiologist is viewing the film as if the patient was in a standard position with respect to the radiologist, such as facing the radiologist. However, a radiograph may be taken with the patient facing towards or away from an X-ray source. To enable the patient information image to be right reading to the radiologist in both exposure situations, one prior art automatic film handling system with a direct imaging camera within the system itself includes two distinct card holding mechanisms for receiving a patient identification card. One of the mechanisms is accessible from one side of the system and the other mechanism is accessible from another side of the system. The patient information card is inserted in the first mechanism if the radiograph was taken with the patient facing towards the X-ray source. The patient information card is inserted in the other one of the mechanisms if the radiograph was taken with the patient facing away from the X-ray source. This prior art system has a distinct illumination source and a different set of optics for reflecting and directing an image from a card in each one of the two card holding mechanisms to the film to be imaged.
All prior art automatic X-ray film handling systems which include a direct imaging camera within the system itself only produce a negative image (i.e., white characters on a black background) of patient information on the film. Light is absorbed by black and reflected by white. Patient ID cards are black typing on white background. As such, light directed towards the patient ID card by prior art direct image cameras is reflected off the white backgrounds of the cards and absorbed by the black typing on the cards. Light imaged on X-ray film makes it black. Thus, the reflected light from the white background of the card is what exposes the X-ray film producing a black field with clear letters on the radiograph. Although a positive image (i.e., black characters on a white background) is typically easier to read, prior art automatic X-ray film handling systems can not produce a positive image of the patient information on the film.
All prior art automatic X-ray film handling systems which include a direct imaging camera within the system itself are limited as to where the patient information can be imaged onto the film such that the patient information is right reading. Upper edge portions of radiographs are frequently held by clips to illumination panels. As such, there is a need to image patient ID information on the bottom of a radiograph, rather than on the top. However, most X-ray film cassettes only have one area blocked by lead to allow imaging of patient ID information subsequent to general exposure of the patient to X-rays. Typically, the blocked area is the upper left corner of the cassette. No prior art automatic X-ray film handling system which includes a direct imaging camera within the system is capable of imaging patient ID information from a card onto this blocked area such that the imaged area is right reading and on the bottom of the film.
No prior art automatic X-ray film handling system which includes a direct imaging camera within the system is capable of adding information to the reflected images or providing the operator with options to change the size, font and/or format of such information.
World markets with diverse equipment offerings and needs demand more flexible assemblies, apparatus and processes for placing patient identification on films and, in particular, on X-ray films in automatic daylight film handling systems.